A DESIGN METHOD FOR AVOIDING FATIGUE FAILURE

OF LARGE FRANCIS TURBINE RUNNER

Huang Yuhua  Wang Dejin  Jian Tao 

(Northeast University of Technology)

Mi Yude  Zhong Su

(Harbin Research Institute of Large Electric Machinery)

Abstract: According to the complicated conditions ans and specific environment of large Francle turbine, a comprehensive design method for avolding fatigue failure is proposed in the paper. The method made use of the theories of random fatigue and corrosion fatigue is based on a large number of statistical data and fatigue experiments. The paper includes the determination of design load spectrum, fatigue charactristion of the materials in corrosive environment, various factors affecting fatigue strength and ways of calculating service life and safety factor etc. The results of this study would supersede static design method of the turbines and can more efficiently evaluate the safety of the turbine against fatigue failure in design or in service.
Key words: Francis turbine  Fatigue strength  Service life  Safety factor
Received 19910205, received in revised form 19911130